Introductory Address.- Massive Binaries - Early Evolutionary Stages.- Binary X-Ray Stars and Supernovae of Type I.- Two Types of Evolution of Massive Close Binary Systems.- Late Stages of Close Binary Systems.- The Post-Supernova Stage of Massive Close Binaries: The Possibility of a Tidal Instability.- The Observational Situation in Regard to Black Holes.- Common Envelope Binaries.- Effect of Instantaneous Mass Ejection on Orbital Elements of Circular Binaries.- Tidal Interactions in Compact Binary Systems.- Observations of Dwarf Novae.- The Eclipsing Binary White Dwarf BD + 16°516.- Spectroscopic Observations of Southern Dwarf Novae.- Spectroscopic Observations of U Gem.- The Cause of the Nova Outburst.- Theory of Dwarf Novae.- Gravitational Radiation and the Evolution of Low Mass Binaries.- Masses and Evolution of Cataclysmic Binaries.- Angular Momentum Loss and the Origin of Cataclysmic Binaries.- Ultraviolet Observations of some Close Binary Systems by the Astronomical Netherlands Satellite - ANS.- Accretion Processes in Close Binaries.- Numerical Simulation of Mass Transfer and Accretion Disc Flow in Binary Systems.- Mass Transfer in Semi-Detached Binaries.- A Hydrodynamical Calculation of Gas Flow in a Cataclysmic Vàriable Star.- Coronae above Accretion Discs.- Mass Flow in Close Binary Systems.- Mass Transfer Rates in Algol Binaries Deduced from Their Period Changes.- The Algols, Red Spectra, Be Stars, and Even Neutrinos.- Notes on the Interpretation of Observations of Circumstellar Matter in Binary Systems.- Observations of Gaseous Disks in Close Binaries.- Starspot Activities as an Interpretation for the Light Curve Changes of the Close Binary Star XY UMa.- Identification of3 He in the Binary System 68u Her.- The Mass-Exchange Binary Sco X-l.-Evolutionary Status of Massive Algols - a Revision of Classical Theory.- Contact Binaries.- Unsteady Mass Loss in Close Binaries.- A Cyclic Thermal Instability in Contact Binary Stars.- Energy Transfer in Contact Binaries.- Progress in Contact-Binary Energy Transfer.- Evolution of Contact Systems.- The Evolution of Contact Binaries.- UBV Photometry of the Shortest Period Contact Binary CC Com.- Four-Colour Survey of W-UMa-Type Systems.- Rotational Angular Momenta of Close Binary System Components.- An Aspect of Star Fission.- Statistics of Binary Stars: Semi-Major Axes.- The Origin of the RS CVn Binaries.- Concluding Remarks.- Author Index.- Star Index.